inter branches voice communications with MPLS VPN

Dear Experts:

We have decided to go for MPLS VPN with full mesh network.  Managed Global VPN with with COS3 100%.  We totally have 04 branch offices and each branch office will have 03 to 04 projects.

Our Network and requirement:

1. 04 branches and each branch have projects on different locations hence totally 14 locations are covered with MPLS VPN with mesh network.
2. We are planning for inter branches communication setup to cut the cost on the telephones calls , but  I do not know anything about the telephony,  all I have heard about asterisk can be used either open source or the business versions.

Please suggest me for inter-branches communications which is connected with the MPLS VPN mesh network will this be a the recommended solution and most importantly what is the name for this solution is it “ Asterisk call manager” or “Asterisk  ip pbx” , I am confused please tell me.

Below points are my doubts please help by clarifying the same:

1.for inter-office communications with IP telephones or any other in the MPLS VPN mesh network which application to be used  please name it and also the application has many modules which module to be used ,so that when having discussion with the service provider will have an idea

2.I prefer linux based, is open source sufficient or should we go for business or commercial product.

3.Is it better to go for commercial version of asterisk so few codecs are enabled where the bandwidth utilization will be less. on open source versions codecs will not be enabled hence bandwidth consumption will be high( i heard about this but not sure how much correct is this), please name the technology name for the solution iam looking for example is it IP-PBX or Call manager iam not sure

4.Also iam not very much particular on Asterisk only in addition if any other solution can be better than asterisk then request to recommended that also.

Please help.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

First off you will want to change up your COS profiles  COS3 of 100% doesnt really do you much good.   YOu may want to construct something like this

COS1 - Voice Data 30%
COS2 - Mission Critical Applications 40%
COS3 - Secondary Apps 20%
COS4- all remaining data - 10%

for #2 - You ask about open source vs commercial.  How many total extensions will you have?  If you do not have extensive experience with VoIP, then I would suggest a commercial system with support.  Phones are essentially a mission critical application.  They need to be available for general business as well as safety.     I would do commercial.   If you want to manage it and do not have extensive experience, I recommend ShoreTel.  it does not get easier to manage and configure than ShoreTel

for #3 How much bandwidth do you have between sites?  How many calls do you estimate will be traversing your data lines at the peak?   You will want to use the codec that provides the best quality while fitting within your bandwidth constraints.  Intrasite you will want a quality codec like G711 or intersite G729

for #4: if you lack the expertise needed to maintain an enterprise level system, then I recommend a commercial solution.  If you want to easily manage the solution, give a hard look at ShoreTel.  When it comes to ease of management, they really cannot be beat.   What is your budget?

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
IP Telephony

From novice to tech pro — start learning today.